Thread: cylinder heads

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theres a good looking set of heads i'm thinking of buying. but the intake ports are bit big. they are 320cc and my motor is 408 cubes. i'm spinning my engine 6500RPM. they are aluminum protopline heads that i can get a good deal on. but i also think the intake is just too big. i'm running solid roller cam 274/280 dur. .640 lift. am i short on cubes? or will i be fine? much help appreciated!

Way too big of a runner!!!! Those heads are designed for a roller cam application with over 300 duration, probably almost .800 lift, and a Dominator carb and pulling up to 8,000 RPM. The good deal won't mean as much when they turn your engine into a boggy pooch!!!!

hey Dave S. are you all right ????????? i know deep down inside your a chevy man .it ok dave i will not tell no one

Theres nuthin better to a ford man ,than to tell a chevy man ,hes got too big a HEAD!!!

Originally Posted by steelsixpack101

theres a good looking set of heads i'm thinking of buying. but the intake ports are bit big. they are 320cc and my motor is 408 cubes. i'm spinning my engine 6500RPM. they are aluminum protopline heads that i can get a good deal on. but i also think the intake is just too big. i'm running solid roller cam 274/280 dur. .640 lift. am i short on cubes? or will i be fine? much help appreciated!

the cam is a bit to big ? but i do not know what you want .but them heads would work if you rpm the hell out of it. you would be much better with a smaller runner head and a smaller cam ? but if it a 13.5+cr engine put the heads on it and rpm it to the moon. hope you have good stuff in the bottom end. and a good oil pan? the small bores on the 396/402 may need some work on them for the intake valve if it a 2.300

Originally Posted by steelsixpack101

theres a good looking set of heads i'm thinking of buying. but the intake ports are bit big. they are 320cc and my motor is 408 cubes. i'm spinning my engine 6500RPM. they are aluminum protopline heads that i can get a good deal on. but i also think the intake is just too big. i'm running solid roller cam 274/280 dur. .640 lift. am i short on cubes? or will i be fine? much help appreciated!

These heads might work if you have 14 to 1, on alky,8,500 rpm's, 5,500 stall,and a transbrake in a rail that weighs around 2,000 lbs.

Originally Posted by erik erikson

These heads might work if you have 14 to 1, on alky,8,500 rpm's, 5,500 stall,and a transbrake in a rail that weighs around 2,000 lbs.

i like the big cid big blocks. but all ways wanted to build a 13.5 cr roller with a big stick in it. 396 with a rock soild bottom end and some big killler heads and put it in my goat for the hell of it. and come out at 8500 but to do this it would be the same almost to build the big stuff i do. had some small big block back in 1980 and ran good but were mild and i beat a lots of stuff .they were a fun engine you could get a engine for about $50 bucks

I wouldnt be to scared of the heads if you put a small manifold and carb on it. Keep in mind, those heads are smaller than most ported stock rec port heads and will move more air. I wouldnt recomend it at all if you have less than 10:1. That cam is going to hurt you worse than anything. What is the lobe sep?


http://www.svrehorsepower.com

Originally Posted by S V R E

I wouldnt be to scared of the heads if you put a small manifold and carb on it. Keep in mind, those heads are smaller than most ported stock rec port heads and will move more air. I wouldnt recomend it at all if you have less than 10:1. That cam is going to hurt you worse than anything. What is the lobe sep?


http://www.svrehorsepower.com

The intake manifold is an extension of the cylinder heads.
If you have a smaller intake runner and then you do an intake gasket match to meet the heads in other words you made the exit of the intake runner larger you just lost all your port velocity.
Always try and match your components.
For an example. If the cam pulls to 7,000K then you heads,intake and carb need to do the same thing.

Here at the Nextel Cup shop where I work, we tune a lot of engines with the manifold.